Chicken extracts were manufactured from broiler breast hydrolyzed by three different enzymes of Pepsin, Papain and Bromelain. The pH value was adjusted to the most suitable value for different enzyme before or during the hydrolysis every two hours until 15 hours. The volatile basic nitrogen (VBN) and amino nitrogen were evaluated. When VBN value risen rapidly and closed to 30mg%, the hydrolysis stopped. The hydrolysates were analyzed for free amino acids and sensory evaluation. No matter the adjustment of the pH value, the VBN value of Pepsin didn't rise significantly during 15 hours (P＜0.05). Regarding Papain and Bromelain, the VBN value of adjusted pH value before hydrolysis risen rapidly after 7 and 9 hours' hydrolysis, however, the VBN value of other pH group risen rapidly after 9 and 11 hours of reaction. Among three enzymes, Pepsin was showed highest amino nitrogen level than others than others. Two pH treatments were indicated no difference on amino nitrogen. In addition, the hydrolysates of Papain had the highest ratio of bitter amino acids. The results of sensory evaluation also pointed out the same result that Papain hydrolysates had the strongest bitter intensity, which was 5.4 (P＜0.05). Pepsin hydrolysates exhibited the best overall acceptance, which was 5.2 (P＜0.05).
